What is the role of screening in the management of abdominal aortic aneurysms?

Abstract

A best-evidence topic in vascular surgery was written according to a structured protocol. The question addressed was whether screening asymptomatic individuals for an abdominal aortic aneurysm (AAA) is feasible and improves disease-free survival. Seven studies presented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results and limitations of the studies are tabulated. In total, four randomized population-based studies have evaluated ultrasound screening for AAA: two British studies, Multicentre Aneurysm Screening Study (MASS) and the Chichester trial, and one each in Viborg County, Denmark and Western Australia. Participants were randomized to receive an invitation to screen or not. The MASS trial randomized 67 770 men, followed participants over 10 years and concluded that screening would almost half AAA-related deaths in men aged 65-74 years. The smaller Chichester trial included only 6040 men but demonstrated a 42% reduction in AAA-related mortality at 5 years, with ongoing benefit at 15 years (11% reduction). The Viborg County trial recruited 12 639 men aged 64-73 years, showed a 66% reduction in AAA-related mortality over 14 years. Finally, the Western Australia trial evaluated 41 000 men but included an older population of 65-83 years old. No benefit was seen in this age group but subgroup analysis of men aged 65-74 showed a significant mortality benefit. Only a small or insignificant benefit in all-cause mortality was seen in any of these studies. A recent meta-analysis of these trials has shown a significant benefit in AAA-related mortality in the long term and concluded that AAA screening is superior to other established screening programmes. The cost-effectiveness of screening was assessed in the MASS and Viborg County trials and was found to be substantially below the cost threshold set by the National Institute of Clinical Excellence for acceptance of interventions. Quality of life was assessed in the MASS and in a case-control study and showed no adverse effects that outweigh the benefits. We concluded that ultrasound screening for AAAs has met all the criteria to become a screening programme and would substantially reduce disease-related death with no adverse effect on quality of life.

Rastreio do aneurisma da aorta abdominal – revisão baseada na evidência

“…19 Esta conclusão já tinha sido obtida numa MA anterior (Lindholt et al); 10 como também a alguns aspetos da RS da Cochrane, uma vez que nestas revisões foram incluídos dados relativos às mortes de um ECAC (Western Australia) não ajustados para a idade. 18,20 Foram ainda incluídas 7 NOC, a maioria realizadas no norte da América (quadro III). Ferket et al realizaram uma análise qualitativa de muitas das NOC incluídas nesta revisão, tendo sido aquelas com pontuações de rigor mais elevadas a da USPSTF (79%), da American College of Cardiology/American Heart Association (ACC/AHA) (63%) e a do National Screening Committee (NSC) (41%).…”

Abdominal Aortic Aneurysm : Aspects on how to affect mortality from rupture

“…Regarding mortality from rAAA, the number needed to screen (NNS) for AAA to avoid one death in rAAA is 238, with corresponding figures for colorectal---and breast---cancer being 671 and 1339 respectively (Dabare et al 2012). …”

Influence of rurality, deprivation and distance from clinic on uptake in men invited for abdominal aortic aneurysm screening

“…Screening for abdominal aortic aneurysm (AAA) in men aged 65 years using portable ultrasonography has been launched recently in Scotland and elsewhere in the UK. The effectiveness of AAA screening in men is supported by evidence from four randomized clinical trials, which have demonstrated that screening reduces AAA‐related deaths, but without any impact on overall mortality. Uptake among invited men in these four clinical trials ranged from 70 to 80 per cent.…”

“…The effectiveness of AAA screening in men is supported by evidence from four randomized clinical trials, which have demonstrated that screening reduces AAA‐related deaths, but without any impact on overall mortality. Uptake among invited men in these four clinical trials ranged from 70 to 80 per cent. AAA screening in the Grampian region of north‐east Scotland was launched in October 2012 as part of a national population‐based screening programme.…”